Draft control for furnaces



VMarch 29, 1938.

M. DE LIN DRAFT CONTROL FOR FURNACES 1956 2 Sheets-Sheet l Filed June 8V,

Ill

March 29, 1938. M. DE LIN 2,112,272

DRAFT CONTROL FOR FURNACES Filed June 8, 1956 2 Sheets-Sheet 2 l Patented Mir. 29, 193s PATENT OFFICE 4 nam coN'moL Foa mNAcas Munn De un, nounou, nnen., mimmio n1- land Furnace Company, Holland, Mich., a corporation oi Michigan application :une s. 193s. serial No, 84,111 s 4 cum. (ci. izo-l-zs'n The present invention relates to furnaces. particularly to means for controlling the draft therethrough; and its object is. generally, to provide such means improved in various respects hereinafter set forth; and more particularly, to provide a plurality of draft controls having means foroperating `the same alternately or relatively to each other; and further, to provide draft controls for the radiator ring and the smoke dis- 10 charge therefrom respectively and means for thus operating the same: and further, to provide said controls and a control for the air inlet and meansfor operating the same alternately or relatively to each other: and further, to provide means for thus operating the controls by the opening and closing -of thev closure for the fuel-supplying door ofthe furnace; and further, to provide adjustable means for thus operating the controlsv selectively.

These and any otherl and more specific objects hereinafter appearing are attained by, and the invention-finds preferable embodiment in, the illustrative furnace structure particularly described inV the -body of this specification and illustrated by the accompanying drawings, in

which:-

. Figure 1 is an elevational front view of a hot air furnace provided with draft controls and means for operating the same;

Figure 2 is a like view showing the controls in another. relative position;

.Figure 3 is a like view showing the controlsy in still another relative position;

Figure 4 is a horizontal sectional view of portions of the structure taken on line 4 4 of Figure l; and

Figure 5 is a horizontal sectional view of other portions taken on line -5-5 of Figure l.

The hot air furnace illustrated by these drawings has'the combustion chamber l enclosed by of said chamber for heating air in the casing to be'discharged through suitable hot air pipes 1,y and the smoke pipe 8 leading to the chimney.

This draft passage has at several points along its length controls for the draft therethrough,

such controls including: the closure lid 9 for said air inlet I (desirably formed through yclosure, lq

of the door I i through which ashes and the like under the grate are removed), this lid being pivotally mounted to swing by its weight to the closed position shown in Figures 2 and 3; an opening to the combustion chamber, being the door i3 through which fuel is supplied thereto, having the closure i2; a damper il turnable by its shaft I 5 to the closed position shown in Fisures A1, 2 and in solid lines in Figure 4 to cause the smoke to pass in the direction indicated by l0 the arrows in Figure 4 from the combustionchambers outlet 5 and through said ring in order to more effectively heat the air inside the casing,

this damper being turnable a quarter way-around to open position shown in Figure 3 and in dotted 15A lines in Figure 4 to permit the smoke to pass more directly from said outlet i into the smoke pipe 8 to thus lincrease the force of the draft through said draft passage and the chimney; and the checkV draft opening I8 through the wall of the 20 smoke pipe having. a closure lid I'l plvotally mounted to swing by its weight to the closed position shown in Figures l and 3.

These draft controls are moved relatively toeach other to closed or open positions by operat- 25 ing means including cables secured to vthe controls respectively and a suitable cable-adjusting device for tautening or slackening the same, the illustrated form of such a device including a turnably mounted shaft i9 having crank arms 30 20, 2| manually turned as by the knob handle 40, A cable,.the chain 22, passing over pulleys indicated at 2K3, 24, 25, 26 is secured at one end to the crank arm 20 and at its other end to the lid 9, this chain's length being such that when said 35 crank arm is turned to lower position shown in Figure 1 the chain is tautened to raise said lid and open the air inlet I; but when this crank arm is turned to upper position shown in Figures 40 2 and 3 the chain is slackened to permit said lid to fall to the position shown in these views and close said air inlet. A cable, the chain 28, passing over pulleys indicated at 29, 30 is secured at one end to the other crank arm 2| and at its 45 other end to the lid i1, this chains length being such that when the crank arm is turned to lower position, in the interrelative position of certain of the draft controls as shown in Figure 2 (and as hereinafter explained), the chain is tautened to 50 raise said lid and open the check draft opening I8 as seen in said view; but when this crank arm is turned to upper position shown in Figure 1 (in said relative position of the draft controls) the chain is slackened to permit this lid to fall to 55 the position shown in that view and close said check draft opening.

In another interrelative position of such draft controls as shown in Figure 3 (and as hereinafter explained), this chain 23 is slackened to permit the lid I'l to fall and close the check draft opening I6 when the crank arm 2| is in lower position shown in said view.

The closure I2 for the fuel-supplying door I3 hingedly mounted at 3l has an outwardly extending arm portion 32 to which one end of a cable, the chain 33, is secured at 34, and passing over pulleys indicated at 35, 36, 31 this chain is secured at its other end to the crank arm 38 of the shaft I5. The weight of this arm urges the damper I4 to open position shown in Figure 3 and in dotted lines in Figure 4.

When the latch 39 is turned to released position seen in Figure 3 and the closure I2 is opened as shown in that view, this chain 33 is slackened to permit the arm 38 to fall and open damper I4 thus causing the smoke to pass directly from the combustion chambers outlet 5 into the smoke pipe 8, so that smoke will be carried by the draft thus increased through the chimney and will not pass outwardly from said chamber through the fuel opening I3; but when the closure I2 is shut the chain 33 is tautened to raise arm 38 and again close the damper I4.

The parts of the means for operating the draft controls are so combined and operatively connected as to function in an improved manner for attaining certain desirable ends. For instance:

although the purpose of the control damper I4 is to direct the draft through the radiator ring for heating the air in the furnace casing., this damper thus used tends by obstructing the draft passage to choke it with soot, etc.; the check draft control I6, I'l has no such air heating effect but it does not obstruct the draft passage to choke it with soot.

It is therefore desirable to employ these draft controls at times selectively and alternately, although both are to be employed to increase the draft when the furnace doors closure I2 is open. To effect such alternate use the chains 28, 33 are so connected that the movement of one affects that of the other. In the illustrated construction, this connection is made by engaging the hook end 4I of the block 42 of the pulley indicated at 30 with a link of chain 33.

In Figure 1 the shaft I9 of the adjusting device I8 is shown turned to the position wherein the draft controls are held thereby in that interrelative position in which the furnace operates in its usual air-heating manner; that is, the lid 3 is open and the damper I4 and the check draft lid I'I are closed, the closure I2 being also closed.

In Figure 2 the shaft I 3 has been turned to the position wherein the draft controls are held thereby in that interrelative position in which the draft through the combustion chamber is decreased and fuel consumption is lessened; that is, the lid 9 is closed and the lid I'I is opened, but the damper I4 continues closed to heat the radiator ring.

In Figure 3 the shaft I9 remains in the same turned position as in Figure 2 so that the lid 3 remains closed, but the closure I2 having been opened the chain 33 is thereby slackened to permit arm 38 to fall and open damper I4, and the sidewise mutually deflected relation of chains 33 and 28 and their length below the pulleys 31 and 23 have been so changed that, mutually acted upon through their connection (the pulley 38 and its block 42), the opening of closure I2 Opens damper I4 and closes lid I'I (Figure 3) and the closing of closure I2 closes damper I4 and opens lid I'I (Figure 2) the lid 9 remaining closed in both cases; and that in the oppositely turned position of shaft I3 and lid 3 is opened and the damper I4 and lid II are closed in the closed position of closure I2 (Figure 1).

The weight of the crank arm 38 is desirably great enough to swing the unlatched closure I2 to open position. The hook end 4I of block 42`may be engaged with any of the links of chain 33 in order to adjust the required deflection thereof, and one lof the crank arms 20, 2| may be held by a set screw indicated at 43 in desired turned position on shaft I3 to adjust the relative annular position of these crank arms. A coiled spring 44 in chain 33 renders the same somewhat elastic to cushion its action.

The invention being intended to be pointed out in the claims, is not to be limited to or by details of construction and arrangement of the particular embodiment thereof illustrated by the drawings or hereinbefore described.

I claim:

1. In a furnace having a combustion chamber with a fuel-supplying door provided with a closure and a draft passage having an air inlet provided with a closure lid said passage including a smoke pipe having a check draft opening provided with a closure lid and a radiator portion between the chamber and the pipe provided with a damper closed to conduct smoke through said portion and opened to conduct smoke directly into the pipe,

means for operating the damper and the lids by the opening and closing movements of the closure including: a cable extending between the closure and the damper tautened by the closing movement of the closure to close the damper and slackened by the opening movement -of the closure to open the damper: an adjusting device; a second cable extending between said device and the lid of the check draft opening; a third cable extending between said device and the lid of the air inlet; and a pulley movably in engagement with the second cable, lhaving a hook manually adjustable in connection with the rst cable. the adjusting device being movable to a position wherein the first cable tautened to close the damper tautens the second vcable through said connection to open the lid of the check draft opening and slackens the third cable to close the lid of the air inlet, the adjusting device being movable to another position wherein the first cable tautened to close the damper slackens the second cable to close the lid of the check draft opening and said device in its same position tautens the third cable to open the lid of the air inlet.

2. In a furnace having a combustion chamber with a fuel-supplying door provided with a closure and a draft 'passage having an air inlet provided with a closure lid said passage including a smoke pipe having a check draft opening provided with a closure lid and a radiator portion between the chamber and the pipe provided with a damper closed to conduct smoke through said portion and opened to conduct smoke directly into the pipe, means for operating the damper and the lids by the opening and closing movements of the closure including: 'a cable extending over a pulley between the closure and the damper and tautened by the closing movement of the closure to close the damper and slackened by the opening movement of the closure to' open the damper; an adjusting device: a second cable extending over a eolid pulley between said device and the lid of the `check draft opening; a third cable extending between said device and the lid of the air inlet; and a connection manually adjustably joined to the first cable between the first pulley and the damper and having a pulley carrying the second cable between the second pulley and-the lid of the check draft opening, the adjusting device being movable to a position wherein the rst cable tautened to close the damper tautens the second cable through said connection to open the lid of the check draft opening and slackens the third cable to close the lid of the air inlet, the adjusting device being movable to another position wherein the first cable tautened to close the damper slackens the second cable to close the lid of the check draft opening and said device in its same position tautens the third cable to open the lid of the air inlet.

3. In a furnace having a combustion chamber with a fuel-supplying door provided with a closure and a draft passage having an air inlet provided with a closure lid said passage including a smoke pipe having a check draft opening provided with a closure lid and a radiator portion between the chamber and the pipe provided with a damper closed to conduct smoke through said portion and opened to conduct smoke directly into the pipe, means for operating the damper and the lids by the opening and closing movements of the closure including: a cable extending between the closure and the damper tautened by the closing movement of the closure to close the damper and slackened by the opening movement of the closure to open the damper; an adjusting device including a rotatable shaft with Aa pair of crank arms; a second cable extending between one arm of said device and the lid of the check draft opening; a third cable extending between the other arm of said device and the lid of the air inlet; and a connection including a member manually detach ably engageablewith the first cable at selected positions in the length thereof and having a pulley carrying the' second cable, the shaft being turnabie to a position wherein the first cable tautened to close the damper tautens the second cable through said connection to open the lid of the check draft opening and slackens the third cable to close the lid of the air inlet,` the shaft being turnable to another position wherein the first cable tautened to close the damper slackens the second cable to close the lid of the check draft opening and said device in its same position tautens the third cable to open the lid of the air inlet and the arms being turnable on the shaft to selected angularly spaced secured positions thereon.

4. In a furnace having a combustion chamber with a fuel feed door and a draft passage having a damper, a draft inlet door and a smoke pipe with a draft check, flexible connecting means between the draft inlet door and the draft check consisting of chains and means connected thereto eective to open the draft check when closing the draft inlet door and vice versa, flexible connecting means between the feed door and the damper for opening the latter when the former is opened and vice versa and consisting of a single chain, and a pulley over which the check controlling chain passes, said pulley having means manually adjustably engageable with a selected link of the damper controlling chain for holding slack out of the check controlling chain when the damper is closed and permitting the check controlling chain to slack to close the check when the damper is opened.

MARTIN DE LIN. 

